Breaking New Ground for Juniper a Management Handbook for Lowland England Contents

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Breaking new ground for juniper A management handbook for lowland England Contents

Purpose and scope 5 Lowland juniper – the facts 6 Conservation status and distribution 6 Habitat 7 Wildlife dependent on juniper 7 Identification and life cycle 8 Conservation challenges and solutions 9 Without The factors underpinning regeneration 10 Site assessment 12 Management options 14 action Habitat restoration 14 Juniper restoration management flowchart 15 Scrub clearance 16 Bare ground creation 17 Minimising browsing 20 now Seedling surveys 23 juniper Enhancing germination 24 Reinforcement and reintroduction 26 faces Propagation, planting and protection 30 Monitoring and aftercare 34 Documenting 34 Appendix 1: Step-by-step guide to seed processing 36 extinction Appendix 2: Propagation protocol for subsp. hemisphaerica 37 Useful references 38 across Key contacts 39

much Written by Tim Wilkins and Dr Jenny Duckworth of This publication would not have reached fruition without its many the contributors. Particular thanks are owed to Lena Ward, Jonathan Crewe, English Rachael Arden, Julia Carey, Barry Clarke, Stuart Corbett, Nicky & Richard Gould, Alistair Griffiths, Penny Jones, Shelagh McCartan and Chris Trimmer. We are indebted to landowners, site managers and propagators who have lowlands deftly turned management theory into reality and in doing so helped shape this guide. In addition, the following companies have given much appreciated advice at no cost: the Caledonian Tree Company, Cheviot Trees, within Petersfield Growing Mediums and Trees Please. Cite as: Wilkins, T.C. & Duckworth, J.C. (2011). Breaking new ground for juniper – a management handbook for lowland England. Plantlife, Salisbury, UK.land. 50 years Plantlife, Salisbury, UK. Juniper has declined across Britain but the problem is particularly acute in the lowlands, We are Plantlife where it has been lost completely from 9 The UK’s wild plants have been marginalised and taken for of its 27 lowland vice-counties, including granted for too long. Wild plants clean our air and water, Bedfordshire, North and South Essex, North provide food and shelter for our insects, birds and animals and Devon and North Somerset. Populations that will be critical in the fight against climate change. are still surviving in the Chilterns, Sussex and Wiltshire have shown declines in juniper abundance of 84%, 69% and 44%. Many Plantlife is the organisation that is speaking up for nation’s wild colonies have dwindled to such an extent that plants. We work hard to protect wild plants on the ground and to they are functionally extinct. build understanding of the vital role they play in everyone’s lives.

Front cover photograph: Calstone Down, Wiltshire. © Sharon Pilkington, Vegetation Survey & Assessment 02 Foreword Breaking new ground for lowland juniper 03 Purpose and scope

This guide contains detailed advice to aid the recovery of juniper (Juniperus communis subsp. communis) across the chalk and limestone country of lowland England. Plantlife has been piloting a series of management techniques with project partners to fi nd out the best ways of triggering regeneration and rehabilitating functionally extinct colonies. Although these trials are still ongoing, we hope this guide will equip conservation practitioners, land managers and voluntary groups with the information they need to stem the wholesale decline of the species across southern England. In the absence of wider landscape-scale processes ushering in a whole new generation of juniper, clusters of small scale restoration projects have potential benefi ts beyond the level of individual sites.

This publication forms part of a two-year project ‘Saving England’s Lowland Juniper’, funded by Natural England, Biffaward and Buckinghamshire County Council.

The guide addresses the fi rst lowland BAP action (2008) for juniper, namely: bring research together to establish a detailed management protocol. In so doing, it is hoped the remaining lowland BAP actions will be achievable: • Apply [the protocol] to key sites within core areas • Restore and expand appropriate habitat • Ensure grazing is at appropriate levels on all sites • Establish ex-situ seedbank to reinforce highly isolated and edge- of-range single-sex populations with re-introductions where Starved of light, these appropriate mangled skeletons of For information on managing juniper in upland situations, please refer to the booklet entitled ‘Managing Uplands for Juniper’ which is juniper sit beneath a available for download from the Plantlife website, or in hardcopy from dense canopy of beech. Plantlife’s head offi ce.

Shropshire Lincolnshire West Midland Habitat Cambridgeshire Northamptonshire Juniper can be found growing on a wide variety of soil Worcestershire Suffolk types and topographies but in lowland England today it Warwickshire Bedford chiefl y occurs on chalk downland or limestone grassland. Herefordshire The grassland communities that support juniper (Box 1) central Bedfordshire are frequently species rich themselves, containing other threatened plants such as wild candytuft, musk orchid Hertfordshire Gloucestershire Buckinghamshire and pasquefl ower. These wild fl owers stand to benefi t from Oxfordshire Monmouthshire Essex habitat management for juniper.

Other typical habitats include: ancient trackways, paths S.Gloucestershire Swindon and waysides, disused quarries, cliff faces, earthworks and London area West rarely heathland. N.Somerset Berkshire BANES Wiltshire Surrey Where scrub or young woodland have colonised, juniper Somerset Kent will slowly die out. Ironically, its prickly foliage may Hampshire hasten woodland development by acting as a nurse

West Sussex tree for other species – e.g. yew. At some Chilterns sites East Sussex juniper has been lost under beech although this may be a consequence of historical plantations. Pasquefl ower © Photo credit

Dorset post 1990 species records Isle of Wight pre 1990 species records Box 1. Lowland plant communities The National Vegetation Classifi cation communities listed below refl ect the diversity of calcareous Figure 1. Juniper decline across grassland habitat that juniper inhabits. Remarkably, only CG2 and CG7 typically feature bare ground lowland England – pre-1990 sites in red; 1990-2010 sites in blue (based on which is considered a prerequisite for juniper seedling establishment. The other communities may 1km square and 100m square records). therefore be sub-optimal for recovery. Derived from MiniScale by Ordnance Survey. Reproduced from Ordnance Main lowland grassland communities supporting juniper: Survey digital map data. © Crown • CG2a Festuca ovina – Avenula pratensis grassland, Cirsium acaule – Asperula cynanchica sub- Lowland juniper – the facts Copyright 2011. All rights reserved. community • CG2b Festuca ovina – Avenula pratensis grassland, Succisa pratensis – Leucanthemum vulgare sub- Conservation status and distribution community • CG3a Bromus erectus grassland, typical sub-community Along with Scots pine and yew, juniper is one of only three conifers native • CG3d Bromus erectus grassland, Festuca rubra – Festuca arundinacea sub-community to Britain. Although a long-lived perennial, in southern England there are • CG5a Bromus erectus – Brachypodium pinnatum grassland, typical sub-community very few sites where juniper is regenerating successfully. • CG7 Festuca ovina – Hieracium pilosella – Thymus praecox/pulegioides grassland

Juniper’s lowland headquarters lie in the South Aston Rowant in the Chilterns is the only other SAC Wessex Downs, where it is particularly abundant primarily designated for juniper scrub in southern Wildlife dependent on juniper on the military ranges of Bulford and Porton Down. England. Elsewhere juniper occurs more sporadically Juniper is almost a habitat in its own right, and its stems and branches can support a range of These two areas support the largest remaining across the chalk and limestone, where the majority supporting an impressive range of wildlife, including lichens and bryophytes. populations in southern England, with thousands of good populations are either designated SSSIs or some species that could not survive without it. of bushes each, and are considered to be the best NNRs. Typical hotspots are the Cotswolds, Chilterns, Juniper berries and shoots provide a food source for Bare ground around juniper can attract a variety of remaining examples of lowland juniper scrub on and the North and South Downs (Fig. 1). wild birds and mammals, especially during autumn early successional plants and wildlife. Species such chalk. Their inclusion in the Salisbury Plain Special and winter months and it supports over 50 insects, as kidney vetch and horseshoe vetch are important Areas of Conservation (SAC) gives them formal Owing to its BAP status, juniper is a Species of such as the juniper shield bug, juniper aphid and food plants for butterfl y larvae, with the former the recognition under the EC Habitats Directive Annex I Principal Importance in England (S41 of NERC Act juniper carpet moth. Juniper also provides ideal sole larval food plant of the small blue – a Species habitat: ‘Juniperus communis formations on heaths 2006). It is currently listed as ‘Least Concern’ in The habitat for spiders. Studies show that the larger of Principal Importance in England (S41 of NERC or calcareous grasslands’. Vascular Plant Red Data List for Great Britain but the populations of juniper, the greater diversity of Act 2006). Similarly, butterfl ies that require a short this is on account of its long lifecycle and relatively insect species. In addition, over 40 species of fungi sparse turf stand to gain, e.g. the Near Threatened gradual decline throughout Britain as a whole. are either entirely or partially dependent on juniper, silver-spotted skipper.

06 Lowland Juniper - the facts Breaking new ground for lowland juniper 07 Identification and life cycle Conservation challenges

© Pat Woodruffe © Pat With the exception of a small population of subsp. hemisphaerica on the Lizard peninsula in Cornwall, and solutions all lowland populations comprise subsp. communis - hereafter simply referred to as juniper. Taxonomically, After the last Ice Age, vast stony landscapes relatively free these subspecies may be relegated to varieties in future. of wildlife were commonplace, providing ideal conditions for juniper to flourish. There have since been pulses of regeneration Juniper is unusual in that it has a variety of growth forms, across the lowlands linked to complex changes in land use. Most ranging from prostrate to columnar. Upright bushes can recently was in the mid-1950s, in the wake of the Myxomatosis reach four metres or more in height. Juniper’s foliage is outbreak, when the sudden drop in rabbit numbers led to the emergence of a whole new generation of bushes. The majority of composed of small and densely packed prickly needles that LITTLE OR grow in whorls of three. Close up, a whitish stripe of stomata junipers in the south today owe their existence to that event. NO BROWSING (sometimes two stripes) can be seen running down the upper Today’s heavily managed countryside side of each needle (Fig. 2). has little in the way of suitable habitat for juniper. Annual cycles of grassland BARE GROUND From a distance, juniper can be confused with yew or gorse management conflict with its reproductive but yew is generally a larger tree with comb-like shoots strategy and, despite its prickly foliage, composed of soft, dark green needles. Female yews carry juniper is often damaged by livestock, red ‘berries’ in the autumn. Gorse is a grey-green shrub with Figure 2. The distinctive stomatal stripes on upper rabbits and deer, with its seedlings sides on juniper needles. distinctive yellow flowers for most of the year and its spines CONSERVATION MANAGEMENT particularly palatable. Figure 3. Male flowers cones in May lack the white stripes. Top picture – pollen sacs full; Bottom – pollen sacs empty) The problem is currently perpetuated Be aware that there are also a great many garden varieties by a tendency to manage conservation and non-native species of juniper which can be confused grasslands uniformly, resulting in a paucity LOWLAND CALCAREOUS GRASSLAND with J. communis, particularly boundary and hedgerow trees. of bare ground and a seasonal risk of browsing from livestock (Fig. 4). Juniper is dioecious – its bushes are either male or female. Figure 4. Current rarity of juniper regeneration habitat Female bushes are usually easy to identify because of their small blue-black or green berries (strictly speaking cones or As lowland junipers typically live for 100-120 and mites that hollow out the seeds. At many ‘galbuli’). A lack of berries is a good but not totally reliable years, they have up to 100 opportunities to juniper sites in southern England, their impact sign that the bush is male. Young females may be berryless reproduce successfully. If each individual is is substantial. Juniper seed can also abort due to sexual immaturity and isolated females may fail to survived by just one offspring, a stable population during development due to false pollination develop berries due to lack of pollination. Male bushes are will result. For this reason, and because of juniper’s by air pollutants or even dust. Fragmented generally taller and produce minute flower cones in spring tendency to reproduce episodically, the absence populations and biased sex ratios can further with abundant pollen (Fig. 3) that are slightly different in of seedlings at a site for a decade or more should impede pollination through distance or barriers. appearance to those of females. After flowering, the remains not be a cause for great concern. However, today of male cones may be seen for some time, allowing bushes to many populations consist entirely of old collapsing The transient nature of juniper seed means that be sexed reliably. bushes which are prone to sudden die-off. Urgent it fails to form a persistent seed bank in the soil. intervention is clearly needed at such sites. This fact alone makes revival of lost populations Juniper has adapted to be mobile through efficient seed impossible without resorting to translocation. dispersal. The berries on female bushes ripen two or three Although good berry years can produce years after pollination which occurs by wind. In the autumn, prodigious quantities of seed, less than 2% Juniperus communis is declining in other parts of berries fall onto the ground beneath bushes or are eaten may be viable. Combine this fact with the lowland Europe. Computer modelling suggests that and dispersed by birds or animals. Migrant thrushes such ubiquitous threats of browsing, trampling, shade, its European range will contract northwards as the as fieldfare, redwing and mistle thrush are particularly desiccation and disease, and it becomes clear climate warms, implying a greater international responsible. Seedlings are slow-growing and take 4-9 years to why seedlings are so scarce. One study showed responsibility to conserve its populations in reach sexual maturity. Juniper also has the facility to spread that out of 10,000 seeds, only 6 produced the UK. An emerging concern in Britain, is the locally through layering (a means of vegetative reproduction seedlings that survived their first year. trend for increasingly mild winters which may whereby branches resting on the soil form roots). This eventually result in a failure to break seed appears to rarely happen on the dry soils of the south and its Poor seed viability occurs naturally in many dormancy (juniper seed requires two cold winters significance has yet to be determined. small-seeded pioneer tree species. The to germinate). Furthermore, young seedlings situation is, however, exacerbated by insects are highly susceptible to summer drought.

08 Lowland Juniper - the facts Breaking new ground for lowland juniper 09 The factors underpinning regeneration Another key condition is suppressed succession, limiting the impact of faster-growing or taller SLOW As a pioneer species, the proximity of bare ground species outcompeting or overshading juniper SUCCESSION appears to be the most important factor responsible during its development from seedling to for seedling establishment. Areas that remain reproductive adult. Succession is naturally continuously open with plentiful bare ground are slowed through a combination of impoverished much more likely to support seedlings. Episodes skeletal soils and naturally eroding or steep of intense bare ground creation need to be slopes. Preventing soil enrichment is the key to followed by long periods of little or no disturbance. suppressing succession. BARE MINIMAL Traditional activities such as droving, shepherding, GROUND BROWSING or occasional cultivation, would have created such High light levels are clearly associated with conditions. Similarly, ancient trackways, earthworks juniper establishment. Although one study and old quarries provided ideal habitat and are The intensity of rabbit and deer has shown successful growth in 20% daylight, typical juniper haunts today (Table 1). Currently, browsing in combination with livestock higher light levels tend to yield higher growth regeneration is largely confined to a few roadside levels is crucial in determining seedling rates. Seedlings growing directly beneath parent bushes will perish in persistent deep shade. MEDIUM-HIGH embankments although some of these colonies survival and growth. Browsing levels LIGHT LEVELS originated as introductions (Fig. 5). may need to be low for 10 to 15 years before seedlings are sufficiently robust. The diagram in Fig. 6 summarises the interplay of these conditions. Note that not all need be PERSISTENT OPEN BARE GROUND true at the same time – e.g. a period of high WITH LOW BROWSING PRESSURE grazing pressure creating bare ground may be followed by little or no grazing. Figure 6. Key regeneration conditions.

Figure 5. Natural colonisation on a Wiltshire roadside bank © Pat Woodruffe

Habitat Site examples Causal factors Downland and grassland Porton Down (Wilts) • Fluctuating rabbit population – Bulford Down (Wilts) e.g. post-myxomatosis (1954-5) Rodborough Common (Gloucs) • Controlled grazing (poaching) • Terracettes on slopes (e.g. sheep paths) • Protected sites Old/ancient quarries Noar Hill (Hants) • Abundant bare ground Painswick Beacon (Gloucs) • Steep slopes • Cycle of abandonment and re-use • Minimal grazing when quarried • Protected sites Waysides, ancient routes and Aston Rowant (Oxon) • Long-standing use earthworks Stockton Down (Wilts) • Route changes (cycle of abandonment Winterbourne Downs (Wilts) and re-use) Roundway Down (Wilts) • Stock movements/funnelling (poaching Fleam Dyke (Cambs) intensity gradient; minimal browsing) Figsbury Ring (Wilts) • Sunkenways and slopes (natural erosion/ soil creep) • Protected sites Wild animal tracks, burrows Stockton Down (Wilts) • Badger setts and diggings • Habitual animal tracks

Table 1. Principal lowland juniper habitats, with factors considered responsible for juniper’s persistence.

10 Conservation challenges and solutions Breaking new ground for lowland juniper 11 Site assessment Box 2. How to assess seed viability The cut-test is a reliable, albeit destructive, way of determining seed viability. It can be done in the Before management options can be considered, some key facts about the fi eld but accurate dissection and examination is best done off site. site and any surviving juniper must be known. Equipment Site information needed: Locking knife, cutting board (e.g. back of old clipboard), hand lens (x10), notebook and pen. Alternatively, • grazing levels if checking berries off site: sample bags or envelopes, a low-powered binocular microscope, scalpel and – if • pressure from rabbits and deer storage required – use of a domestic fridge. • amount of bare ground (%) • location of good juniper habitat (open, unshaded, thin poor soils, Collecting sloping, pockets of bare ground) • Seed viability can vary a great deal between individuals and stands. Take small samples of berries from: • presence/restoration potential of early successional fl ora and fauna  All females for small colonies (< 30 bushes) • proximity of ruderal infestations  At least 50% of females for medium colonies (30–100 bushes) • proximity of mixed scrub and young woodland  At least 20% of females for large colonies (>100 bushes) • proximity of fi eld vole habitat (tall grassland) • Pick no more than 20 ripe berries per bush (plump blue-black berries are ripe; leave those that are green or • location of key conservation features brown). If bushes have very few berries, collect one berry for each 10 available. • location of key heritage features • Use a sharp knife on a fl at hard surface to cut ripe berry cross-ways (equatorially), • access routes for excavator cutting through seeds. • management plan and long-term aims • If you intend to collect seed for propagation afterwards, keep a record of each bush’s seed viability, along with its location (GPS or sketch map) and the availability of ripe berries. • If collecting berries for examination later, bag and label each sample.

Examination Population information needed In the fi eld, cross-sections should be examined with a hand-lens. Off site, a low-powered binocular microscope (also refer to Seedling surveys section): is useful. If checking at a later date, store berries in breathable containers (e.g. paper bags) in a fridge. • abundance: small colony <30 bushes; medium 30-100; large >100 Viable seed is always fi lled with a white/creamy interior (endosperm) – Fig. 7. If the seed is brown or hollow For small and medium sized populations, try to record the inside, it is almost certainly unviable. Note that not all fi lled seeds will germinate but the test gives a good location of every bush (use a GPS) along with the following estimation. If intermediate seed is found (e.g. incompletely fi lled, or endosperm slightly brown) consider these attributes: doubtfully viable.

• sex Berries are occasionally galled by insects/mites and the seed eaten. • age class (seedling, young, mature, over-mature, dying and dead) Figure 26 shows some types of damage and the species responsible. • level of seed viability (Box 2) • amount of disease/physical damage Results • berry abundance (especially ripe berries) Calculate the mean seed viability per bush and per colony and then refer to the table below. Note that some females may yield samples containing no viable seed. For larger populations, take a representative sample from each stand/colony and record: • a centroid grid reference • sex ratio (% of: male and female) • age structure (% of: seedling, young, mature, over-mature, dying <10% poor and dead) 10-40% moderate 40-60% good When plotted on a map, the spatial distribution of bushes/stands along with their attributes may reveal weaknesses in the population >60% very good structure, allowing a more strategic conservation approach, e.g. by revealing isolated single-sex stands suitable for reinforcement. Viable seed Unviable seed

 Figure 7. Typical cross-section of berries & seeds

12 Site assessment Breaking new ground for lowland juniper 13 Management options Juniper restoration management

On sites where juniper has steadily dwindled and consistently failed KEY THREATS to regenerate, intervention is likely to be unavoidable to secure Scrub / Woodland • heavy shading / succession recovery. There is no silver bullet: juniper seed is slow to ripen and Juniper in mixed scrub or under tree canopy • impeded pollination germinate, seedlings are slow growing and can take up to 9 years to • impeded dispersal reach sexual maturity. Ex situ techniques may decrease the recovery PHASE I MANAGEMENT PITFALLS time but aftercare may be necessary for 5-10 years after planting. • Scrub clearance • accidental damage • Stump treatment • bushes more prone to collapse, windthrow or snow damage All restoration projects should run for at least 10 years. • Control of re-growth • death by light shock (particularly etiolated bushes) • increased exposure to livestock, rabbits or deer. Habitat restoration is the key to long-term recovery, without it additional measures such as reinforcement will prove unsustainable. Restoration is also likely to be of far greater ecological benefit (see Wildlife KEY THREATS Long grassland • insufficient bare ground (seedling habitat) dependent on juniper). Where juniper colonies have poor seed viability, or Juniper in ungrazed/uncut grassland • seedlings overshaded imbalanced sex ratios, a combination of in situ and ex situ techniques can • deer (browsing & debarking) be highly effective. • small mammals (berries, seed or seedlings eaten) PHASE II MANAGEMENT PITFALLS • Enclosure • damage by machinery or stock (especially hardy breeds) There are three broad approaches to management: • Stock grazing or cuttng • hidden seedlings exposed to damage (introduced or increased) • deer damage unchecked 1. Habitat restoration (facilitating natural regeneration) 2. Assisted regeneration (enhancing germination) 3. Reinforcement or reintroduction (transplanting) Short grassland KEY THREATS Juniper in grassland grazed by stock • grazing animals (browsing, rubbing, trampling) Fig. 8 shows the pathways to regeneration for a range of lowland habitats. Under • insufficient bare ground (seedling habitat) and/or rabbits • soil enrichment each management phase is a breakdown of the steps required. Although we have placed techniques to stimulate natural regeneration ahead of translocation, it PHASE III MANAGEMENT PITFALLS is possible to skip or combine phases (so long as the chances of future natural • Controlled grazing or pinch points or • soils too rich/deep (attracts ruderals or tree seedlings) ground scrapes (unsown) • insufficient seed reaches bare ground regeneration are uncompromised). Where viable seed and bare ground co-occur, SUCCESSFUL • Seed-shelters or seedling REGENERATION • spiny brash piles not replenished we advise waiting at least three years for juniper seed to germinate (see Seedling protection or grazing relaxed • seed-shelters not removed after re-vegetated • exclosures not rabbit proof surveys) before progressing to the next phase of management. • exclosures/shelters fail to last 5 years • lack of monitoring (annual seedling surveys) • problems managing site long-term for natural re-gen

Habitat restoration KEY THREATS The management sections on pages 16-25 give a broad range of Scree / Rocky ground • low seed viability Juniper on/by unvegtated ground - • poor sex ratio / skewed distribution options. Each option begins with a checklist of desirable attributes to e.g. quarries or scrapes • population small and fragmented help you determine its suitability. • single cohort of over-mature bushes • conversion to arable or other land use The following are additional: PHASE IV MANAGEMENT PITFALLS • At least one male and one female bush on site (otherwise reinforce) • Seed sown or • planting/sowing area proves unsuitable • Average male:female ratio more balanced than 5m:1f (otherwise reinforce) SUCCESSFUL cultivated bushes planted • insufficient numbers planted/sown REGENERATION • Seedling/transplant protection • unprocessed seed sown • Female bushes with abundant ripe berries (if needed) • low survival rate due to poor planting • Skeletal soils (poor and thin) • planted outside of autumn • transplants are clones of one stockplant • Open sloping land (unshaded) • bushes in cultivation too long • Low risk of mixed scrub encroachment • sexes poorly mixed, or too few female bushes • incorrect guard used for seedling/transplants • Low risk of ruderal infestations • lack of annual weeding • Presence or records of other important early successional species • exclosures/shelters fail to last 5 years • Other site features uncompromised (biological, archaeological, amenity, etc) • lack of monitoring (annual seedling surveys) • problems managing site long-term for natural re-gen

The more of these characteristics your site possesses, the greater the likelihood of achieving natural regeneration. Figure 8. Management flowchart for non-regenerating stands. Select main habitat type and follow steps of management phase beneath. Prevailing threats for each habitat are listed alongside, as are potential drawbacks of each management phase.

14 Management options Breaking new ground for lowland juniper 15 Scrub clearance Bare ground creation Suitability: • Juniper surrounded by young woodland/mixed scrub Controlled grazing • Grassland restoration scheme ongoing The removal of trees/shrubs surrounding Suitability: • Low numbers of rabbit and deer juniper needs to be phased over two or more • Enclosed cattle-grazed grassland • Livestock type/breed prefer years, rather than clear-felled in one season. • Cattle breeds that rarely browse broadleaf scrub to juniper This should allay the risks of light shock and • Medium to large stands of male and female collapse. Even after gradual clearance some bushes Where the original habitat has succeeded into mixed scrub limbs may break under their own weight or • Low numbers of rabbit and deer or young woodland, restoration is likely to take considerably through increased exposure to wind and snow • Seed viability moderate-very good (>10%) more time and resources than on grassland. The overriding (Fig. 10). Only prune back bushes if necessary, threat is lack of light, which causes a progressive weakening using sharp clean tools. High impact cattle-grazing during the ‘berry drop’ period of shoots and stems (etiolation) and eventual death of of Oct-Dec should create ideal conditions for natural bushes. The reproductive potential of etiolated bushes is Removing the scrub barrier may expose bushes regeneration through poaching (>10% bare ground Figure 11. Controlled grazing can produce copious germination likely to be extremely low. Furthermore, isolated females are to livestock, deer and rabbits. If goats or cover) – Fig. 11. Afterwards the site should be allowed to microsites unlikely to receive much pollen nor attract birds to disperse hardy breeds are being used to control woody recover and extensively grazed as appropriate. Seedling seed (Fig. 9). Ground conditions in mixed scrub are generally Figure 12. Gateway pinch point regrowth, monitor bushes regularly for browse surveys should take place annually for the next few unsuitable for seedling establishment due to a thatch of damage. In cases of severe damage, some form years (see section below). Provided the sward will sustain organic matter and heavy shading. of exclosure may be needed (see Protection). no permanent damage, the regime may be repeated if no seedlings appear. Weighing up the existing ecological value of the scrub/ After each round of clearance, a flush woodland against that of liberating the juniper colony will of vegetation re-growth is usual. Before Some damage to adult bushes (e.g. broken branches) determine the way forward. Where scrub is diverse and controlling this, it’s advisable to carry out a may be unavoidable. If young bushes or seedlings are mature and juniper scattered and in low number, it may seedling survey (section below). In the absence present and cannot be protected (see Grazing exclosures) be of greater overall benefit to translocate the colony to of grazing, an annual ‘cut and remove’ regime use another technique to create bare ground. nearby grassland, or another open habitat, that can be may prove a good alternative but care should managed appropriately. The relic bushes should be used be taken to avoid damaging bushes and to donate cuttings and berries for ex situ propagation (see seedlings. If herbicide is to be used, choose Reinforcement and reintroduction). equipment that eliminates the risk of drift. Pinch-points Suitability: © Pat Woodruffe • Cattle-grazed grassland Figure 13. Poaching of ground around water trough • Cattle breeds that rarely browse • Small distinct stands of male and female bushes, or satellite females • Low numbers of rabbit and deer • Seed viability moderate-very good (>10%)

Pinch-points are narrow gaps through which livestock routinely pass, creating patches of disturbed ground. They can result from natural obstructions (e.g. scrub) but are more commonly associated with gateways (Fig.12). At some sites, it may be possible to create pinch-points in the vicinity of berry-clad females using fencing, or through the strategic placement of water troughs (Fig.13). Although places where animals congregate or lay up tend to become nutrient enriched and have there will be a gradient of disturbance either side higher browsing pressure, the routes to these places may that may provide suitable microsites for germination provide ideal habitat. and growth.

Poaching is more intense where tracks are sunken or Consideration should be given to reinstating routes bounded by banks, ditches or fences. Animals driven or that have fallen into disuse such as old drove roads Figure 9. Surrounded by young scrub, this healthy bush is ridden along such tracks have relatively little time to and sunken ways, especially where old bushes survive. doomed without intervention. browse adjacent vegetation - including juniper. Although Opening up routes for public recreation (e.g. as Figure 10. Sudden clearance of mixed scrub can lead to bush collapse. trampling may be too intense, and soil too compacted, bridleways or mountain bike trails) may offer for juniper seedlings to establish in the track centre, a good alternative.

16 Habitat restoration Breaking new ground for lowland juniper 17 Natural regeneration – On sites with acceptable Scrapes seed viability (average >10%), a scrape immediately Suitability: downslope of, or adjacent to, females with ripe berries • Wide range of habitats should be effective. Juniper seedlings have been (grassland, mixed scrub, ex-arable) observed growing along fence lines and beneath trees • Wide range of seed viability due to bird perching, so creating bird perches over (depending on berry availability) scrapes may help. • Low numbers of rabbit and deer • Compartment extensively grazed or Assisted regeneration - Where it is unfeasible to ungrazed for a period create a scrape adjacent to females bushes, or seed Figure 16. Sowing seed across a scrape in Wiltshire • Livestock type/breed that rarely browse viability is altogether poor (<10%), a good alternative • Access for excavator is to sow the scrape by hand (Fig. 16). This has some distinct advantages over natural colonisation because Unlike areas subject to continual erosion, scrapes will Scrapes are areas that have been scarified by machine Large scrapes are preferable to small ones as they slow scrapes can be: gradually revegetate and can close over in as little as five or manually (depending on size) so that no vegetation down succession and discourage herbivores by offering • sited optimally years. Juniper’s inherent slow germination and growth, remains. They are a quick way of generating bare ground neither food nor shelter (Fig.14). Shape is generally • located to create links between isolated colonies means that seedling establishment is effectively a race in the right place but do not persist. Careful siting unimportant but long narrow scrapes are best avoided as • sown at other times of year against time. Monitor during this period to identify of scrapes is critical to their success. Excavators are they are less of a deterrent to herbivores and will more (although autumn is thought best) changing management needs (see Seedling surveys). advantageous on deep soils and where arisings need rapidly revegetate. • sown with cleaned and screened seed to be moved, but on thinner soils ploughing or power (see Enhancing germination) If a scrape has been created on heavily grazed land, harrowing may suffice. Scrapes should be as shallow as possible to expose or there is an acute threat from rabbits/deer, it may be the maximum amount of bare rock/stone (Fig. 15). However, this method may be subject to translocation necessary to install an exclosure fence. Scrapes reduce the risk of berry foraging by voles and A preliminary ‘test dig’ is highly advisable to check protocols and is more labour intensive, requiring seed However, this should only be considered a temporary - to a lesser extent – wood mice. Protecting seedlings the soil depth, which can vary over remarkably harvesting, processing (see Enhancing germination) measure – see Grazing exclosures. Seed shelters may from small mammals may be unnecessary unless tall short distances. On areas cleared of mixed scrub, and sowing. offer another alternative. grassland develops harbouring field voles (Box 3). stumps can be removed during scrape creation. Soil arisings should be taken away from the scrape site rather than bunded around the edge, or piled close by, because topsoil may contain ruderal seed that on flowering will seed back into the scrape. Box 3. Small mammals – friends or foes?

wood mouse seldom impact negatively on juniper Gould © Richard regeneration.

No evidence was found of these species attacking juniper seedlings nor young stems despite past reports of damage by voles (particularly field vole). However, voles did occasionally gnaw the bark of adult bushes. Damage to roots by field vole was negligible but the junipers studied rarely occurred in long grass – typical field vole habitat. Overall, rabbits and sheep were considered to have a much greater impact on seedling survival than small mammals.

Figure 17. Berries de-seeded by wood mice Both bank voles and wood mice were found to eat juniper berries (Fig. 17) but generally only a small proportion of those available were taken (although this Figure 14. Created for juniper, a 400m2 chalk was expected to increase over the winter as alternative Berry foraging and caching may be beneficial to scrape on the South Wessex Downs food sources diminished). Foraging by wood mice was juniper. Seedlings were frequently found associated Figure 15. Newly dug, this Cotswolds limestone more intense beneath bushes that provided a close with bank vole tunnels and the caching of berries scrape has been sown with hundreds of seeds sheltered environment. Nevertheless, seedlings were away from parent bushes may act as a means of still noted in areas of relatively high berry foraging. seed dispersal.

18 Habitat restoration Breaking new ground for lowland juniper 19 Minimising browsing Box 4. How to install seed shelters

Regardless of whether shelters are to be sown or not, To prevent small mammals tunnelling under and Seed shelters installation sites will generally need scarifying or raiding berries, it is advisable to sink shelters into the Suitability: turf-stripping by hand (a mattock is ideal). The ground ground at least 4inches (10cm). Backfilling should • Stock-grazed grassland (especially sheep) beneath shelters should be rocky and as far as possible help secure the shelter but anchoring posts or pins • Small to medium fragmented juniper colonies free of vegetation and soil. Test the soil depth first may be necessary on steep slopes (Fig. 20). • Large populations of rabbit, deer or small and choose another location if deep or rich soils are mammals encountered. • Wide range of seed viability (depending on berry availability) The stripped areas will generally close over after a few years, leaving little time for seedlings to establish. Plantlife is trialling specially designed shelters to Natural regeneration – This is only feasible where To slow down the succession, scarify an area slightly prevent berries and seedlings from being eaten (Fig. 18). there is a female bush in the open with plentiful ripe larger than the dimensions of the shelter (Fig. 19). The seed shelters are made of galvanised welded wire berries and good seed viability (average >10%). Shelters mesh (13mm - mesh size; 16g - gauge) stapled onto should be installed in autumn before berry drop, treated timber frames. The mesh size has been carefully September being the best time. Earlier installation is not chosen to keep out small mammals yet is large enough recommended because this will reduce the window for to allow juniper berries to fall through onto the ground. germination and growth as the sward inside becomes a Shelter The shelters are hinged for flat-packing yet readily competitive threat. Assign one shelter per female bush, assembled on site with four bolts. The tops are removable installing it in the berry ‘drop zone’ but far enough from to aid seedling monitoring. Shelter dimensions are: the trunk base to avoid overshading. Sloping ground 120cm x 120cm x 30cm and a less conspicuous half- is advantageous as shelters can be sited further away size version: 60cm x 60cm x 30cm. The shallow height downslope. On exposed sites make allowances for the allows shelters to be positioned close to female bushes prevailing wind direction. whilst not inhibiting seedling growth. Refer to Box 4 for installation details. Assisted regeneration – Where there is a lack of suitable installation sites beside female bushes, or seed viability is universally poor (<10%), shelters can be sown by hand. This has some distinct advantages over natural colonisation because shelters can be: • sited optimally • located to create links between isolated individuals/groups Turf-stripped ground • sown at other times of year (although autumn is thought to be optimal) • sown with cleaned and screened seed (see Enhancing germination)

However, this method may be subject to translocation © Jonathen Crewe protocols and is more labour intensive, requiring seed © Jonathen Crewe harvesting, processing and sowing. The large Plantlife shelters were sown with 50 seeds and the small shelters with 15 but optimum sowing rates are not yet known.

Shelters should be monitored at least annually (see Seedling surveys) and remain in situ until there is no appreciable bare ground left (usually after 3 to 4 years), after which they should be removed and if possible reused. Seedlings may need a further period of protection, depending on levels of browsing, trampling, etc until they are sufficiently robust (see Monitoring and aftercare). Field voles may pose an additional risk Figure 18. Large seed shelter where seedlings occur in tall grass (Box 3). Figure 19. A good installation on de-turfed ground Figure 20. Shelter with anchoring posts beneath adult female

20 Habitat restoration Breaking new ground for lowland juniper 21 Grazing exclosures Box 5. A less obtrusive approach to management Suitability: • Stock-grazed grassland Piles of spiny brushwood create a less conspicuous barrier to herbivores and can be used in two ways: (especially cattle, ponies or horses) • Small to large juniper colonies (clustered bushes) • Large populations of rabbit or deer • Barriers around the bases of productive female or • Wide range of seed viability male bushes, mitigating browse and bark damage (depending on berry availability) (Fig. 23). This approach has been successfully • Frequent bare ground pockets, demonstrated at a site in Buckinghamshire, or pre-prepared scrape Well-sited juniper exclosures should remain beneficial however seedlings may appear directly © Jonathen Crewe • Absence of tall grassland in vicinity for about 5 years, after which they gradually become beneath parents. counterproductive without some form of vegetation Fenced exclosures (Fig.21) can be expensive and are control. Once the exclosure vegetation has closed over, • Loose mats or rings of spiny brash on open bare often reviled as a last resort but on heavily grazed sites there are several options: ground (scarify or deturf if necessary). Seed or they provide an effective way of facilitating natural • remove the exclosure completely berries can then be cast within, or bird perches or assisted regeneration. To be successful, they need • allow grazing animals occasional access (lightly created above. Note that juniper will not establish careful siting, monitoring and maintenance. graze) in deep shade, so avoid making mats too dense • manually weed - carefully strip/cut back overgrowth As with shelters, areas with the thinnest poorest soils (moss carpets can be scratched out with a spring-tine Refer to the suitability criteria given for seed shelters. and abundant bare ground should be chosen. At least rake) Brash piles should be checked and replenished from one productive female (with good seed viability) and time to time to remain functional. ideally a mixed-sex group with several females should Seedling junipers will probably need guards installed be included. If seed viability is universally less than before exposing them to grazing animals (see Figure 23. Encircled by thorns, this young bush 10%, enclosing a seeded scrape will likely yield greater Protection). If tall grass dominates, there may be an is afforded greater protection from rabbits success. additional risk from field voles. Maintaining a shortly mown strip around the outside of exclosures may help Several small exclosures are usually preferable to a deter voles. single large one. The smaller size makes them easier to check and maintain, and if a fence is breached not all Fenced exclosures, shelters and guards may be Seedling surveys junipers will be at risk. Small exclosures can however be considered eyesores or an unwanted expense. A cheap Seed usually starts to germinate in the second spring easily forgotten (Fig.22). and more natural alternative is given in Box 5. Keep a record of exact numbers and locations; if time after reaching the ground due to the need for two allows note height and condition too. Shelters, guards winters to break seed dormancy. However, earlier and exclosures will help mark spots on the ground but germination is possible depending on when seed a GPS unit is useful back-up and a means of digitising matured on the bush. Germination peaks after about locations. Photographs are also a helpful reminder and 2.5 years but may continue for up to 5 years. provide a simple way of monitoring changes in the sward.

The best time to look for seedlings is in May Monitor seedlings at least annually. Growth or June although they can be inconspicuous rates vary considerably but typical maximum in grassland so a thorough ‘hands and knees’ seedling heights are: 5cm in the first year, 14cm search is advisable (Figs. 24 & 25). in the second and 23cm in the third.

  Figure 24. Prime seedling habitat © Richard Gould Figure 25. Vigorous seedling

22 Habitat restoration Breaking new ground for lowland juniper 23 Enhancing germination Box 6. Top tips for collecting berries Equipment / materials: collecting bags or containers, work gloves, eye protection (advisable), ‘berry Berry harvesting Seed processing catcher’ (e.g. upturned umbrella, bucket, tray or ground sheet), GPS, notebook & pen. Only ripe berries should be collected, which are smooth, By removing the flesh of the berry and cleaning the • Keep a record of each parent bush (GPS grid ref, • Collect from as many different females plump and purple-black in appearance. Harvesting is seed, the rate of germination can be more than doubled. age class, approximate number of berries taken, as possible best carried out between late-September and the end Germination is thought to be inhibited by chemicals in by whom); these details can be databased off site • Ignore sickly looking bushes and those with of October: too early and some berries will be unripe; the fruit pulp, an adaptation to aid dispersal by birds • Label containers/bags to cross-reference with abundant insect/mite damaged berries too late and ripe berries will have been eaten by birds and animals. Juniper tends to produce a high quantity of written record • Avoid green or brown berries or those that are and other wildlife. Genetically, it is better to collect a dead seed, although this can be readily removed through • For large populations, it may be impractical to blue-black wrinkled few berries from a large number of bushes than many flotation. Appendix 1 gives a step by step guide to record every bush, in which case, keep separate • Whilst on site, remove invertebrates berries from a single individual. Look out for insect/ processing seed and Fig. 29 shows the finished product. collections for each stand or colony and debris from the container mite damaged berries and avoid collecting these (Fig. • Collecting berries one at a time is impractical. - e.g. through winnowing. 26). If there are few female bushes, or few berries on the A good alternative is to brush off berries with a • Process berries to remove seed as soon as possible bushes, harvest no more than 30% of the total available gloved hand while holding a container beneath (Appendix 1) as they are a good food source for wildlife which (Figs. 27 & 28, options listed above). consequently disperse the seed. Box 6 gives further harvesting tips. Figure 27 Figure 28 Seed viability is easily checked in the field for each female or a representative sample of the population (Box 2). The results can be useful for estimating the number of berries required for assisted regeneration. As a guide, a one litre container holds approximately 4000 berries, with each berry containing one to three seeds (rarely four). However, the amount of viable seed may be a small fraction of this. Figure 29. Fully processed seed

Figure 26. Insect and mite damage to juniper berries. Image kindly supplied by Lena Ward.

Storing seed and stratification Sowing Juniper seed can be readily stored without degrading. Sowing should be undertaken in the autumn before the Ensure the seed is dry (moisture can cause mould), onset of winter. Although seed can be sown immediately Juniper seed chalcid before putting in a loosely-tied plastic bag and then in a after processing, without stratification germination will domestic fridge (about +4oC). Stored in this way, the seed normally take at least 18 months. deteriorates very slowly (over a number of years). Juniper shield bug The amount to sow will depend on the size of the also on other garden Juniper seed is classed as ‘deeply dormant’ because scrape but also seed availability. As a rule of thumb we Conifers in the UK it will only germinate after experiencing a series of suggest sowing up to 30 viable seed per sq m. Only a Eriophyid gall mite most serious in south seasonal temperature changes. It is possible to shorten small fraction of this is likely to germinate and survive the dormancy period by emulating the seasons. the seedling stage. Appendix 1 includes a guide to Preliminary results from Forest Research trials suggest measurement. Juniper scale that seed subjected to two weeks of warm temperatures Introduced in UK followed by an indefinite cold period triggers the highest A record should be kept of the sowing date, the number germination rate in just 40 weeks. In the absence of sown, and exactly locality (use a GPS). Pass this incubation facilities, similar conditions can be recreated information to your local biological records centre or using a cellar for the warm period and a fridge for the cold. the county botanical recorder (Botanical Society of the British Isles), or Plantlife.

24 Enhancing germination Breaking new ground for lowland juniper 25 Reinforcement and reintroduction Site reintroduction should only be considered once the causes of loss have Attempts to trigger natural regeneration can fail for a variety of reasons such as imbalanced sex ratios or colony fragmentation impeding pollination. been identified and resolved. In cases If restoration is impossible, or attempts have consistently failed, it may where the original habitat has been be appropriate to reinforce or reintroduce colonies. Such action should altogether lost, severely damaged or only be taken as a last resort and guided by policy - see JNCC (2003) is beyond restoration, an alternative under Useful References. Ultimately the colony created should be of sufficient size to be self-sustaining under the right management. nearby site should be sought.

Early consideration should be given to the suitability of habitat at the intended planting Translocations can generally be prioritised as follows: site. Areas recently cleared of mixed scrub/ woodland are unsuitable unless woody re-growth To help you determine whether reintroduction or 1. Reinforcement of a small colony (less than 30 bushes) has been successfully controlled, or a scrape reinforcement is suitable for the recipient site, the to address an imbalanced sex ratio, rejuvenate age has been created. Potentially suitable planting sections below begin with a checklist of desirable structure, or link isolated stands (inter-planting) habitat includes: stock-grazed grassland, ex- attributes. The following are additional to these: 2. Creation of a neighbouring colony when conflicting arable fields (impoverished soils only) and conservation interests mean that suitable habitat cannot • Reasons for past decline identified and resolved disused quarries (with compatible after-use). be restored for an existing stand – e.g. over-mature bushes • Open habitat with at least 10% bare-ground cover The receptor site should be agreed by all trapped in woodland of high conservation value • Extensively cattle grazed most of the stakeholders well in advance of planting out 3. Reintroduction to a recently extinct site time; occasional mob-grazing feasible where suitable habitat exists • Low/controlled browsing pressure Propagation takes time: cuttings will need at 4. Reintroduction to a historical site where suitable habitat exists from rabbits and deer least two years growth before they are ready for 5. Creation of a new colony within juniper’s known historical range • 10 year aftercare plan feasible planting; seeds can take five or more years due to • Skeletal soils (poor and thin) their inherent dormancy. Populations with low seed • Open sloping land (unshaded) viability (Box 2) are better suited to propagation • Low risk of mixed scrub encroachment Translocations need careful planning to be from cuttings. Cuttings are quicker growing but • Lack of tall grassland in the vicinity successful and to avoid damaging features can have high failure rates and result in clones (field vole habitat) of parent bushes. Seedlings tend to have greater of the donor site (the source of cuttings, • Presence or records of other important genetic diversity but seed is slow to germinate early successional species berries or transplants) and the receptor site and seedlings slow to develop. As neither method • Other site features uncompromised (the intended planting area). Although a is straightforward, higher success rates may be (biodiversity, archaeological, amenity, etc) licence from Natural England is not required attained through a specialist tree nursery. to collect seed or cuttings from juniper in For larger projects a combination of plants from the wild, SSSI consents may be needed for cuttings and seed is probably the best strategy, both donor and receptor sites. Permission giving tangible results early on, whilst improving should also be obtained from landowners. the future genetic diversity of the population. Aim to create a colony of at least 30 mixed- sex individuals, including any existing bushes, as this is thought to constitute a genetically robust population. Recovery may be expedited by introducing a higher proportion of females – e.g. a sex ratio of 3 females to 2 males (note that female junipers tend to die earlier than males).

26 Reinforcement and reintroduction Breaking new ground for lowland juniper 27 Box 7. Local provenance

Juniper is genetically very diverse. It appears the isolation of some populations has, over time, led to inherited traits developing. Even populations a short distance apart can be genetically and morphologically distinct. However, across subspecies communis these differences are too small to be recognised taxonomically.

There are currently two schools of 2. Under rapid climate change species will evolve. To thought on the importance of local maximise juniper’s resilience and adaptability, small provenance with respect to juniper. isolated populations ought to be linked and reinforced, thereby enhancing gene flow and broadening gene pools. 1. To preserve local distinctiveness and To allay the risk of outbreeding depression (reduced fitness maximise survival, planted juniper ought caused by crossing between two genetically distinct to originate from material collected from populations), multiple donor sites should be used and the same population, or in the case of re- sufficient numbers planted. Reintroductions should likewise introduction, the nearest sizeable population. originate from material collected from multiple donor sites.

Revised IUCN guidelines on translocation are due to be published in 2011. It is hoped that the guidelines will reconcile these opposing views and indicate best practice for both reinforcement and reintroduction.

Reinforcement Reintroduction Suitability: Suitability: • Functionally extinct populations (negligible • Juniper known to occur at site in the past, or chance of natural regeneration) site within known historical range • Population ‘repairable’ (natural regeneration • Donor population/s identified (Box 7) possible in future) • Permissions obtained to create a colony of at • Additional donor population/s available if least 30 mixed-sex bushes needed (Box 7) • Permissions obtained to supplement colony to a The decision to reintroduce a BAP species should not total size of at least 30 mixed-sex bushes be taken lightly; consultation will be needed with site stakeholders and a management plan in place to As well as boosting numbers, reinforcement is facilitate long-term recovery. an efficient means of diversifying age structure, balancing sex ratios, linking up isolated individuals/ groups and generally enriching the gene pool. Nevertheless it should be undertaken sparingly, just enough to ‘repair’ the population and kick-start natural regeneration.

Use the information gathered in the Site Assessment to produce a planting plan. If you are planting to improve pollination rates, take into account the prevailing wind direction.

If existing bushes cannot provide sufficient material for propagation (e.g. if only one sex is present), donor material from additional site/s should be sought - see Box 7.

28 Reinforcement and reintroduction Breaking new ground for lowland juniper 29 Propagation from cuttings Box 8. Top tips for taking cuttings The processes of ageing in plants grown from cuttings Equipment / materials: work gloves, secateurs, cleaning solution, plastic bags, marker pen, water- are not known. Such plants are in reality as old as filled mist sprayer, cool box/bag, GPS, notebook & pen. those from which the cuttings were taken and they may suffer from reduced fertility associated with older Collect over the winter (ideally before year-end but no later than mid-February). To capture the genetic plants. For the same reason, cuttings have a distinct diversity, ideally take about 4 cuttings per bush (depending on size of cutting) from at least 30 bushes, time advantage over seedlings in that they are already representing both sexes and the full range of growth forms. Collect extra cuttings to compensate for likely sexually mature. losses during propagation. If there are fewer than 30 bushes, avoid over-pruning by collecting from a neighbouring colony as well (note translocation protocols may apply). Cuttings usually take two growing years before they are ready to be planted out. Keeping bushes in cultivation for Additional considerations: an extended period (e.g. 5 years) so that they are larger and more resilient is likely to reduce survivorship in the Figure 30. Preparation of heel cutting – lower leaves are • Use only clean sharp secateurs • Keep a record of each parent bush (number of wild because of increased transplant shock and a prolonged removed in readiness for striking (sterilise blades by wiping with methylated spirits) cuttings taken, GPS grid ref, sex, age, etc); this may need for aftercare. Conversely planting them young results • Wear thorn-proof gloves be impractical with large populations, instead keep in more rapid establishment; two years ex situ is probably • Select branches with strong leading shoots and few tallies of male and female cuttings collected; these the optimum. berries (avoid sickly shoots) details can be databased at the nursery • Collect long shoots in the field that can be expertly • Label bags with site name, date and a cross- If time isn’t a constraint, stock plants can be raised from dissected at the nursery reference to written record the most vigorous cuttings that in later years will supply • Prevent cuttings from drying out (even on cool © Jamie Single - www.superoots.com numerous cuttings. However, entire colonies created this days) – keep them out of direct sunlight, in plastic way may be less adaptable to climate change because bags and use a mist sprayer they are clones of a few individuals. The effect may be less It’s vital that cuttings are potted up straightaway. If delayed, wrap the cut end of each shoot in damp tissue, significant when reinforcing populations, depending on the with an elastic band to hold in place. Then store cuttings in plastic bags in a cool dry place – e.g. a cellar. In so number of clones introduced. doing they should remain viable for several days. Guidance on taking cuttings is given in Box 8. Under ideal conditions good quality cuttings will start to root in as Figure 31. Air-Pot grown bush Planting little as 6 weeks. Good rooting has been obtained with Figure 32. The Air-Pot range Whether you are planning on re-establishing a colony, or heel cuttings in sharp sand (Fig.30). Nonetheless some expanding an existing one, careful selection of the planting area batches of cuttings inexplicably fail and for this reason we will pay dividends later. Protected areas and nature reserves recommend using a specialist nursery. may provide ideal receptor sites, although undesignated sites that appear unsuitable may still be worth considering if suitable

Alternatively follow the propagation protocol given co Ltd © Caledinian tree habitat can be restored. Programmes of vegetation clearance and in Appendix 2. This was produced by the Eden Project nutrient stripping can in time produce good planting areas. for subsp. hemisphaerica and its suitability for subsp. communis remains untested. Due to the ongoing To maximise the beneficial effects of planting, prepare a detailed destruction of peatlands, Plantlife strongly advocates the planting plan. This will later serve as a useful record of the use of peat-free compost - e.g. Peat Free T2 – produced by introduction. Adopt a naturalistic planting pattern, mixing sexes Petersfield Growing Mediums www.peatfreecompost.co.uk and ages. Reinforcement should be more targeted, addressing imbalances and discontinuities in the population. Figure 33. Natural juniper scrub at Calstone Down, Wilts The use of ‘air root pruning’ pots for propagation may  accelerate growth and increase survivorship after planting Figure 34. Bush cascade, the result of berries tumbling Propagation from seed In the wild, juniper tends to form thickets that are generally down from an upslope female out. The technique produces a dense fibrous root system lacking other shrub or tree species (Fig. 33). For this reason and its that prevents roots coiling and plants becoming pot bound. Reliably raising juniper plants from seed is difficult. susceptibility to competition, the planting of mixed-species stands There is no need to tease out roots during planting, lowering If results are needed within a predetermined is inadvisable. However, broadleaf shrubs are frequently browsed in the risk of damage to root hairs. A well developed root timescale, it is advisable to use a specialist. preference to juniper so the presence of other shrub species in the system will also aid establishment in impoverished soils. Pretreatment is necessary to break dormancy but same compartment may prove not entirely negative. Air-Pots (Figs. 31 & 32) are made from recycled plastic and even then germination times tend to be sporadic. are available from The Caledonian Tree Company: www. It can take five years or more before bushes a large Ideally plant in locations that provide good regeneration habitat – airpotgarden.com/ enough to be planted out. Information on berry e.g. the top of steep slopes (Fig. 34), beside pinch points, or along harvesting, seed processing, storage and sowing the edges of a well used paths or tracks (unmetalled). Also consider is given in the Enhancing germination section. at this stage preventing damage from herbivores – see sections on Detailed guidance on propagation from seed is Protection and Grazing exclosures. available from Forest Research – see Broome (2003) in Useful References. Cultivated bushes are ready for planting when they reach at least 20cm in height (depending on their shape) – see Box 9. 30 Reinforcement and reintroduction Breaking new ground for lowland juniper 31 Box 9. Top tips for planting Protection Choose guards that will be effective against the biggest Equipment / materials: work gloves, mattock or spade, trowel, bucket (to collect leaf litter), shrub and smallest herbivores on site. Preformed shrub-shelters shelters/guards, stakes, ties (to fix guard to stake), mulch mats & anchoring pegs (optional). with a diameter of 20-30cm and height of 60cm should suit most circumstances, providing adequate protection against Great care should be taken when planting Aim to plant out in October-November to allow some rabbits, rodents and deer. Tree guards tend to be too narrow out. Bushes will grow less quickly than during root development before winter and in readiness for resulting in die-back and unnatural bush shapes that may propagation and their roots need to able to spread the surge of root growth in early spring. Planting in reduce survivorship once the guards are removed (Fig. 35). into the surrounding soil. Planting methods will February-March leaves less time for roots to establish, vary according to whether bushes have been imparting a higher risk of desiccation and failure The ideal shrub-shelter material is a fine mesh that allows container or cell grown (e.g. in rootrainers) and over the summer. The problem is more acute on poor light and air to penetrate but prevents shoots growing a host of other factors. The following advice is chalky soils and south-facing slopes. through. If herbicide is to be used to control weed growth, general; ask your nursery for detailed instruction. Figure 35. Tree guards encourage top-only growth, take precautions against spray drift. Avoid solid guards and Adopt a varied spacing pattern that mimics wild leading to a less resilient bush later on. fake meshes coated in plastic as they create warm humid To establish readily, transplants need to be young populations. Competition between bushes will be conditions that may be suboptimal for juniper. with a high proportion of roots to shoots. Well before reduced by planting at least two metres apart which

planting out, ‘harden off’ the young bushes to may be critical when young bushes are of varied © Jonathen Crewe Climatic Plus shelters (Figs. 36 & 37) have a proven track acclimatize them to growing outdoors. Over several height/vigour (e.g. when grown from seed). Where record for juniper and are available from Trees Please weeks, move them from the greenhouse to a sheltered interstitial grassland exists – e.g. glades – allow (Northumberland): http://www.treesplease.co.uk/ location outside for increasingly longer periods. sufficient access for grazing stock. These guards are UV-biodegradable but are stated to last A step-by-step guide to planting a container-grown bush: more than 10 years. 1. Choose a calm cloudy day Fitting a mulch mat /sheet will reduce root desiccation (the 2. Ensure bush is well watered before planting main reason for transplant failure) and reduce competition 3. Dig a square-sided hole slightly wider and deeper than the pot from weeds (Fig. 37). Without mats, it may be necessary to 4. Mix organic matter such as leaf litter, or chopped turves, with the soil manually weed shelters although this can be a difficult and 5. Keeping the bush in its container, adjust the planting depth so that the top of root ball will be just covered time consuming task. with soil once planted (exposed compost will increase water loss) 6. Only expose the root ball at the moment of planting, disturbing the roots as little as possible Figure 36. Climatic Plus shrub shelter installed with two Shelters should be double-staked and fitted tight to stakes and a mulch mat. 7. Badly pot-bound plants have stiff spiralled roots; return them to the nursery for replacement the ground to exclude voles. After 5 years, shelters and 8. In less severe cases, gently tease out coiled roots so that they point away from root ball when planting mulch-mats should generally be removed and if necessary 9. Keep the bush vertical whilst backfilling the mixture replaced with another means of protection.

10. Firm backfill around root ball, gently heel in and water thoroughly © Jonathen Crewe 11. Fit a mulch mat, or place upturned sods around the base of plant but ensuring the stem itself is kept As well as presenting a barrier to herbivores, guards entirely clear stifle the wind. Buffeting of transplants can prevent root 12. Take care not to skewer the root ball when staking the guard establishment. This is a particular problem on exposed sites with thin rocky soils where bushes may be poorly anchored after planting. To prevent guards being blown over, ensure stakes are aligned with the prevailing wind.

A good bespoke alternative is a post and rail triangle or square with toughened plastic/wire netting that can be dug into the ground. Chicken wire should be avoided because shoots grow through and become trapped (Fig. 38). Figure 37. View of mulch mat inside shelter Although post and rail constructions are more sturdy and Figure 38. Chicken wire provides some protection but is stock-proof, considerable time and resources are needed, difficult to remove in later years as shoots become entangled. making them less practical for large planting schemes. On sites where guards are likely to attract complaints or vandalism, mounds of encircling spiny twigs offer a less conspicuous alternative (Box 5). © Jonathen Crewe

On stock-grazed land, a sturdy fenced exclosure or electric fence is best to eliminate the possibility of trampling and rubbing. When multiple threats exist, combinations of rabbit netting and vole guards have been shown to be highly effective (see Grazing exclosures).

32 Reinforcement and reintroduction Breaking new ground for lowland juniper 33 Monitoring and aftercare Bushes should be checked regularly during the first year after planting, and annually thereafter for at least five years.

Aftercare has three key components: 1. Removal of competitive vegetation 2. Maintenance of grazing protection 3. Prevention of desiccation

The control of weeds surrounding planted bushes has been shown to be a major factor determining growth rates and survival. Mulch mats will give transplants a head start but may be considered unsightly. Weed in the spring, clearing a 50cm swathe around the stem of each bush. Most sites will require annual weeding but on fertile soils more frequent weeding is advisable. Where guards are fitted, manually remove detritus and rank vegetation from inside.

The careful application of an appropriate herbicide may offer an efficient alternative particularly for larger planting schemes but should only be used where there is negligible chance of damaging juniper.

Check bushes are still firm in the ground (tread them in as necessary), re-stake loose shrub- shelters and replace torn mulch mats. Check the integrity of exclosure fences; grazed or browsed vegetation inside would indicate a breach. Documenting Although juniper is well adapted to dry conditions, Recording the numbers, sex and emergency watering during droughts, especially exact locations of planted bushes in the first year after planting, is likely to greatly is important. When evaluating the increase survival rates. Spring-planted bushes national status of juniper in the are particularly vulnerable to desiccation. wild, or the conservation value of a particular site, we need to know to Depending on their size at planting, subsequent what degree populations are natural root development and situation, bushes can take as opposed to introduced or enhanced. many growing seasons to become strong enough Please ensure records are passed to to survive in the wild unaided. Before removing your Local Record Centre, Vice County guards or dismantling exclosures, test the browsing Recorder or Plantlife. impact by exposing one or two bushes.

34 Reinforcement and reintroduction Breaking new ground for lowland juniper 35 Appendix 1 Appendix 2 Propagation protocol for Step-by-step guide to seed processing Juniperus communis subsp. hemisphaerica Equipment / materials: food processor, several bowls, spoon or egg-whisk, Juniperus communis subsp. hemisphaerica is a dwarf Potting Media kitchen sieve, tea strainer, paper towels. You will also need access to cold evergreen dioecious shrub. For finished 5L pot plant. 80% Vapogrow seed and modular compost, 10% Perlite running water and, if storing seed afterwards, use of a domestic fridge. standard and 10% sterilised Loam. Propagules 1. Sort through berries one container at Fertilization a time, discarding any green, brown or Stage 1 (unrooted cuttings) No fertilisation required in stage 1. In stages 1-4 use wrinkled ones. Cutting material taken from Gew Graze in early February 1 gram per litre of Osmocote, 12-14 months 15-9-11 and/or October from one year old semi-ripewood tip +2Mgo + TE in growing media. Supplement with a liquid cuttings or semi ripewood cuttings with ripe heel, feed with half strength Peters Excel, 15:5:15 Mgo + TE 2. Mash blue-black berries to release the seed. 6-9cm in length resulted in over 80% rooting success. 0.3g/l on a fortnightly basis. Small numbers of berries can be processed Cuttings taken at the end of February had a higher by rubbing off the pulp by hand using a rooting success. The bottom leaves of cuttings should Temperature fine-gauze sieve but this can be messy be carefully removed with a sharp propagation knife Juniper will survive temperatures of -5°C. At and time consuming. Instead, use a food before the base of cutting is dipped for five seconds in temperatures below -2°C ensure that plants are processor or electric mincer with a medium Synergol 10000ppm IBA. Diluted 1:5.6 giving a 1500ppm protected by fleece. mincing screen (5mm holes) – anything IBA and placed into modules compost mixture 25% finer will destroy the seed. to 75% grit (higher percentage of grit is a necessity Light for high percentage rooting as Juniper dislikes being Ensure cuttings and plants are shaded and away from waterlogged.) Cuttings were watered in and placed on a direct sunlight. Junipers grow well under glass and 3 Put the result into a large bowl and fill with gravel based mist bed in a Venlo glasshouse with bottom when large enough can be moved outside with up to 20 cold water. Stir the mixture with a whisk or heat of 20°C, on electronic leaf activated keeping the percent shading in the UK. spoon to release trapped air, then allow to leaves just moist. It is crucial at all times not to let settle. This can be done in stages if large the cuttings dry out as this will significantly reduce Irrigation numbers of berries are being processed. percentage rooting success. Do not propagate in direct It is crucial at all times not to let the plants dry out as sunlight as can cause scorching. Growing temperatures: this will significantly reduce percentage survival success. 4. Seed that floats is empty and should be Nights: 8-10 ° C Days: Max 16°C. Cuttings taken in The media requires to be free draining as the roots do not skimmed off and discarded (a tea strainer is Feb take up to three months to root. Cuttings taken in like to be waterlogged. ideal for this purpose). Conversely seed that October take up to six months to root. has sunk to the bottom is mainly viable, Spacing Stage 2 Throughout all stages space so that the plants do not and can be sieved off afterwards. Once rooted, wean off cuttings for two weeks by reducing overlap. mist bursts followed by removal from mist bed and 5. Flush the good seed under cold running pot on into 9 cm square pots (during potting on ensure Crop Schedule (Last week in February) water until clean. that root disturbance is kept to a minimum.) Place on mypexed floor in glasshouse with growing temperatures Rooting stage: Up to 90 days (3 months) 6. Allow to drain before tipping onto absorbent of minimum 8-10 °C and maximum 20°C. Weaning: Up to 14 days (2 weeks) kitchen towelling. Stage 2- Stage 3: Up to 364 days (12 months) Stage 3 Stage 3 – Stage 4: Up to 364 days (12 months) 7. Leave at room temperature until dry Pot on 9 cm to 2L pot (during potting on ensure that Stage 4 – Transplantation: Up to 90 days (5 months) root disturbance is kept to a minimum.). Remain in (do not oven-dry). glasshouse on floor in Venlo glasshouse with growing Total Time: Up to 980 days (33 months) temperatures of minimum 8-10 °C and maximum 20°C. 8. Estimate the number of seed by volume. When outside temperatures reach above 5°C place Crop Schedule (October) One level teaspoon (5ml) = about 200 outside on hard standing. Ensure the plants remain seeds. Alternatively, 100 seeds weighs outside and fleece if temperatures go below -2°C. Rooting stage: Up to 180 days (6 months) approximately 1gram. Weaning: Up to 14 days (2 weeks) Stage 4 Stage 2- Stage 3: Up to 240 days (8 months) 9. Keep seed in a household fridge. Pot on 2L into 5L pots (during potting on ensure that root Stage 3 – Stage 4: Up to 364 days (12 months) disturbance is kept to a minimum.). Place outside on Stage 4 – Transplantation: Up to 90 days (5 months) hard standing with shade. Keep the plants outside above -2°C and fleece if temperatures go below this. Total Time: Up to 980 days (33 months)

Preparation for Transplantation Pests and diseases Slightly reduce irrigation of plants over a five month Keep vigilant at all times with regards to monitoring for period to prepare for planting out. Ensure that the plants Pests, Diseases and Viruses. Plants have been attacked are checked with regards to pests, diseases and viruses by Totrix moth. and that these are treated before the transplantation process occurs. 36 Appendices Breaking new ground for lowland juniper 37 Useful references Key contacts

Agate, E. (Ed) (2000). Tree Planting & Aftercare – a practical handbook. BTCV, ISBN 0-946752-25-7. Buckinghamshire County Council National Trust – SW England Julia Carey Simon Ford Broome, A. (2003). Growing Juniper: Propagation and Establishment Practices. Forest Research Countryside Officer Wildlife and Countryside Advisor Information Note 050, ISBN 0-85538-603-7, available as a free download from: www.forestry.gov.uk [email protected] [email protected]

Crofts, A. & Jefferson, R.G. (1999). The Lowland Grassland Management Handbook (2nd edition). Eden Project Natural England English Nature/The Wildlife Trusts, ISBN 1-85716-443-1, available as a free download from: Dr Alistair Griffiths Graham Steven http://naturalengland.etraderstores.com/NaturalEnglandShop/Grassland Curator (Horticultural Science) Senior Reserves Manager [email protected] [email protected] Day, J., Symes, N.C., Robertson, P.A. & Bacon, J. (Ed) (2003). The Scrub Management Handbook. FACT, ISBN 1-85716-745-7, available as a free download from: Forestry Commission Research Agency Plantlife http://naturalengland.etraderstores.com/NaturalEnglandShop/IN124 Dr Shelagh McCartan Tim Wilkins Seed Scientist Species Recovery Co-ordinator Herbert, R. (1999). Using Local Stock for Planting Native Trees and Shrubs. Forest Research Practice [email protected] [email protected] Note 008, ISBN 0-85538-503-0, available as a free download from: www.forestry.gov.uk.

JNCC (2003). A Policy for Conservation Translocations of Species in Britain. Available as a free download from: http://www.jncc.gov.uk/page-2920

McBride, A. (2005). Managing uplands for Juniper. Plantlife Back from the Brink Management Series, ISBN 1-904749-05-4. Available as a free download from: http://www.plantlife.org.uk/uploads/documents/Management-Managing-uplands-for-juniper.pdf

Malcolm, D.C. (2000). Genetic variation and conservation of British native trees and shrubs: current knowledge and policy implications. Forestry Commission Research Report, ISBN 0-85538-412-3.

Thomas, P. A., El-Barghathi, M., & Polwart, A. (2007). Biological Flora of the British Isles: Juniperus communis L. Journal of Ecology, 95(6), 1404-1440, available as a free download from: http://onlinelibrary.wiley.com/ Supported by:

Ward, L.K. (2004). Juniperus communis L. Plantlife Species Dossier. Available as a free download from: http://www.plantlife.org.uk/uploads/documents/Juniperus_communis_Dossier_complete.pdf

Ward, L.K. & King, M. (2006). Decline of juniper in Sussex. Quarterly Journal of Forestry, 100, 263 –272.

Ward, L. K. (2010). Variation in ripening years of seed cones of Juniperus communis L., Watsonia, 28, 11-19. Wilson, S.M. & Samuel, C.J.A. (2002). Genetic conservation of native trees. Forest Research Annual In partnership with: Report, pp 57-62, available as a free download from: www.forestry.gov.uk design - evansbleep.co.uk evansbleep.co.uk - design 38 Useful references & Key contacts Breaking new ground for lowland juniper 39 Registered Office 14 Rollestone Street, Salisbury, Wiltshire, SP1 1DX. UK Tel: +44 (0) 1722 342730 Fax: +44 (0) 1722 329035 [email protected] www.plantlife.org.uk Speaking up for the nation’s wild plants

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